The invention relates to a device for a pivoting coupling, in particular for semi-trailers. Such couplings serve for the connection of a semi-trailer with a traction engine. The first coupling element on the semi-trailer includes a rotary disk pivotal around an axis and incorporated in a chafe plate. On the rotary disk a central pivot is fastened which is detachable with the traction engine via the semi-trailer coupling. This central pivot transfers the pulling forces of the semi-trailer and prevents the unseating of the trailer.
A known pivotal coupling for semi-trailers is known from the German Patent document DE 35 12 977 A1. The pivot bearing between the rotary disk and the chafe plate is formed by an anti-friction bearing in the form of an axial-radial ball bearing. This pivot bearing allows for a relative rotation between traction engine and semi-trailer in a horizontal plane. The disadvantage of this arrangement is that the occurrence of dynamic driving instabilities which have been known for years as sheering, over-steering and under-steering, as Jack-Knife effect and as skidding are not prevented. Driving instabilities of this type have led in the past to numerous severe accidents. They are mainly based on the fact that there exists no buckling safety in semi-trailers with subsequent axes and in dollies, like articulated buses. Furthermore, taxiing is very laborious in the known semi-trailers because, in particular, pushing back the semi-trailer is only possible with frequent follow-up correction.
Another known pivotal coupling for semi-trailers is known from GB 1 205 314. Here, a break device engages on the vertical extension of the central pivot via brake shoes in order to brake the turning movement of the trailer. The disadvantage of this arrangement is that enormous braking forces have to be expended because it engages in the center point of the rotary motion. Thus, much stronger forces are necessary to brake the circular motion of the trailer than if these braking forces would engage on the outer rim of the trailer. Furthermore, no control is provided that measures the dynamic driving conditions and thus activates the brake device in dependence on the momentary condition, this cannot counteract other side motions.
A further pivotal coupling for semi-trailers is known from FR 1 406 826. Here can be seen a similar brake as in GB 1 205 314, only that now the braking is no longer done via brake shoes but via a disk which is arranged on the central pivot. However, through this the above-mentioned disadvantages are not eliminated but rather enormous forces are still needed to counteract side motions in the trailer. Furthermore, there are no swivel ring and guide wedge present that could absorb the relatively great retention forces and tilting forces. Just as there is no mention of a control device that captures the momentary dynamic driving values so that also here side movements, except for the Jack-Knife-effect, cannot be counteracted.